Andrew Roberson and Timothy Shuman authored this bylined article on the development of deference principles and the implications for tax planning and litigation mattes going forward. “It is still too early to predict what will happen to the various deference doctrines, but it seems clear that courts are trending toward narrowly interpreting and applying these doctrines,” they wrote. “This is significant for TCJA regulations, which will undoubtedly be tested in the courts in the coming years.”